Self-delivery of medicaments by patients dealing with temporary or chronic disease states has been enabled by use of portable, external infusion pumps. Use of these pumps has been shown to improve the quality of life as well as the general health of these patients. However, the size, cost, and complexity of these infusion pumps can be a drawbacks for the users. For example, some of the pumps are electronically controlled and must be programmed to supply the desired amounts of medicaments. This prevents many users from accepting the use of this technology.
Hence, there is a need in the art for a convenient form of treatment using infusion pumps that do not require significant programming or technical skills to use. Preferably, such a treatment would be carried out by an infusion device that is simple to use and mechanically driven. It would also be preferable if the infusion device could be directly attached to the body and not require any electronics to program the delivery rates. The medicament would be preferably delivered through a small, thin-walled tubing or cannula through the skin similar to known technologies.
Although the idea of such a simple delivery device is compelling, many obstacles must be overcome before such a device may become a practical realty. One problem resides in medicament supply. Patients vary greatly on the amount of medicament such a device must carry to provide treatment over a fixed time period of, for example, three days. This is one environment where one size does not fit all. Still further, such devices must be safely wearable and not subject to possible accidental dosing. Still further, such devices must be capable of delivering an accurately controlled volume of medicament with reliability. Finally, a device that provides a means for tracking the number of doses of medication delivered is highly desirable to permit a patient or healthcare provider to ensure that the correct amount of medication is administered over a given period of time. It would be further preferred if the cost of manufacturing such a device would be economical enough so as to render the device disposable after use. As will be seen subsequently, the devices and methods described herein address these and other issues.